Lucent Technologies 6000 - Manual (Page 317)

Configuring X.25
Setting up ISDN D channel X.25 support
MAX 6000/3000 Network Configuration Guide 6-31
Figure 6-7. Example of a T3POS configuration
The Lucent T3POS implementation supports the following T3POS features:
• Local, Transparent, Blind, and Binary-Local mode
• T1-T6 timers
• All the control characters, described in Bellcore GR-2803
• Error recovery procedures, described in Bellcore GR-2803 and EIS 1075-V2.1
• DTE-initiated calls
• Host-initiated calls
Protocol summary
This section provides a brief summary of the T3POS protocol. For complete details about the
protocol and the MAX X.25 PAD, see to the documents listed in “References” on page 6-33.
The T3POS protocol provides reliable and efficient data interchange (transactions) between a
host (usually a transaction server) and a DTE (usually a client). The T3POS DTE is usually a
client device communicating through an asynchronous port, while the T3POS host is a
mainframe or server communicating through an X.25 packet network. The T3POS PAD (the
MAX) converts data arriving from a T3POS DTE to a format that can be transmitted over a
packet network. It also ensures reliability and efficiency as described in the protocol
specifications.
Note that the T3POS PAD does not alter, check, or convert the parity of characters it receives
from or sends to the X.25 network or the T3POS DTE. T3POS essentially uses a data format of
8 bits, no parity. The format is actually 7 bits, 1 parity, but the MAX ignores the parity bit.
Cash registers / kiosks
Ethernet
PSTN
Credit card
transaction center
X.25/T3 POS traffic
(D channel)
PPP/MPP traffic
(B channels)
Corporate site
PSDN
PC or terminal
server
Asynchronous lines
Retail outlet